The air we breathe indoors is more harmful: research
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/did-you-think-only-cars-and-factories-spew-out-toxic-pollutants
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/hindu-new-delhi
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/air-pollution
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/indoor-air-pollution
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/health-effects
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/smart-city
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/vehicular-pollution